1. Field of the Invention
This invention generally relates to door mechanisms, and more specifically to a mechanism for controlling the opening and closing of an appliance door or panel.
2. Description of the Prior Art
3. As a result of the sophistication of today's appliances, many of these have a large number of manually operated switches, buttons, or knobs which permit the control or adjustment of the appliance. This is true, for example, in the case of TV receivers which are typically provided with a large number of controls. While some manufacturers have placed some of these controls or knobs on the back of the units where they are out of view, this has made these knobs or controls less accessible and convenient to the user. In some instances, the controls have been placed on the front of the appliance and concealed by a door or panel which can be easily opened by the user to gain access.
The doors or panels provided on appliances, such as TV receivers, can be maintained in the closed, normally vertical, position by means of a simple spring such as a spiral or tension spring. However, the gravity or weight forces acting on the door as it moves from the vertical closed position to the horizontal open position are generally such that the torques exerted on the door are non-linear as a function of the pivoted rotational movements of the door. Since springs are generally linear tension devices, a problem has existed which either provides too much of a closing force when the door is almost in the closed position. This sometimes results in a forceful closing or a snapping action. However, when the effect of the spring action is lessened, the spring may not provide adequate forces on the door. This sometimes results in the door simply opening by itself or dropping to the open horizontal position, particularly when the unit is moved and the door is slightly tilted in the opening direction.
The use of simple springs to control the opening and closing of appliance doors or panels has not, therefore, proved fully satisfactory since the springs, as noted, are essentially linear devices while the forces acting on the doors or panels act in a non-linear fashion.